alias [ {+|-}gmrL ] [ name[=value] ... ]
       For  each  name with a corresponding value, define an alias with
       that value.  A trailing space in value causes the next  word  to
       be  checked  for  alias  expansion.   If the -g flag is present,
       define a global alias; global aliases are expanded even if  they
       do not occur in command position.

       For  each  name  with no value, print the value of name, if any.
       With no arguments, print all currently defined aliases.  If  the
       -m  flag  is  given  the  arguments  are taken as patterns (they
       should be quoted to preserve them from being interpreted as glob
       patterns),  and the aliases matching these patterns are printed.
       When printing aliases and the -g or -r flags are  present,  then
       restrict  the  printing  to  global  or regular aliases, respec-
       tively.  Using `+' instead of `-', or  ending  the  option  list
       with a single `+', prevents the values of the aliases from being
       printed.

       If the -L flag is present, then print each  alias  in  a  manner
       suitable  for  putting  in a startup script.  The exit status is
       nonzero if a name (with no value) is given for  which  no  alias
       has been defined.
